1. Field of the Invention
This invention pertains to the art of providing a static seal between the inner shrouds of stator vane segments and a radially inner seal housing.
2. Description of the Prior Art
The most pertinent prior art of which we are aware is U.S. Pat. No. 3,529,906 of McLaurin et al and has been embodied substantially as illustrated in gas turbine machines which have been manufactured by the assignee of this application.
As we view it, that design employs a static seal loaded radially against the inner diameter of the first stator inner shroud. While the present invention also is a radially loaded arrangement, it is considered to be a superior arrangement to that shown with respect to several drawbacks of that prior art arrangement. These drawbacks include excessive leakage through the seal to the shroud "smile" clearance caused by mismatch between seal segments and shroud curvatures. Also one seal is required per vane segment thus leading to many joint leaks when single vane segments are used. Finally, each joint exposes a relatively large area to the high pressure fluid to be sealed against and requires a complex segment-to-segment linkage system to seal effectively.
It is the aim of this invention to provide an improved seal arrangement which does not suffer from the noted drawbacks of the prior art arrangement.